This invention relates in general to an intravenous ("IV") catheter and introducer needle assembly having an automatic needle retraction system.
IV catheters are used to provide fluid to or withdraw fluid from a patient. In order to properly place an IV catheter in a patient's vein.sub.1 a sharp introducer needle must be used to puncture the skin, tissue and vein wall to provide a path for placement of the catheter in the vein. Typical IV catheters are "over-the-needle" catheters where the catheter is coaxially placed over the needle. The catheter thus rides with the needle through the skin, tissue and vein wall and into the patient's vein. When the needle pierces the vein, blood will "flashback" into the needle and a flashback chamber typically located at the proximal end of the needle. Thus, once the medical technician observes this "flashback" of blood, the medical technician will know that the catheter and needle have been inserted in the vein. The needle can then be withdrawn from the patient and the catheter can be advanced further into the vein.
In recent years, there has been great concern over the immediate disposal of needles after use. This concern has arisen because of the advent of currently incurable and fatal diseases, such as Acquired Immune Deficiency Syndrome ("AIDS"), which can be transmitted by the exchange of body fluids from an infected person to another person. If a needle has been used to place a catheter in the vein of an AIDS infected person, the needle is a vehicle for the transmission of the disease. Thus, it is extremely important for a clinician to properly dispose of the needle to avoid a needlestick with the contaminated needle. Unfortunately, in certain medical environments, such as emergency situations, needlesticks with a contaminated needle can occur if the contaminated needle is not somehow covered immediately after use.
Much effort has been directed to develop an introducer needle assembly that can be shielded after use to minimize the possibility of an accidental needlestick with a contaminated needle. Some assemblies are deficient because the medical technician is required to perform an additional step in order to actuate the needle shielding system after the catheter has been properly located in the patient's vein. In addition, some assemblies are deficient because visualization of flashback is poor.